A charge density study of π-delocalization and intermolecular interactions

2015 ◽  
Vol 17 (21) ◽  
pp. 14177-14184 ◽  
Author(s):  
L.-C. Wu ◽  
W.-C. Chung ◽  
C.-C. Wang ◽  
G.-H. Lee ◽  
S.-I. Lu ◽  
...  

The location of bond critical points (red dots) and its associated bond path (black line) provide the evidence on the existence of the weak intermolecular interactions of the π–π interactions between triazole rings of atrz molecules in crystal with the close ring distance of 3.17 Å.

Author(s):  
Stephen A. Stanton ◽  
Jonathan J. Du ◽  
Felcia Lai ◽  
Gyte Stanton ◽  
Bryson A. Hawkins ◽  
...  

2018 ◽  
Vol 74 (3) ◽  
pp. 170-183 ◽  
Author(s):  
Bertrand Fournier ◽  
Benoît Guillot ◽  
Claude Lecomte ◽  
Eduardo C. Escudero-Adán ◽  
Christian Jelsch

Estimating uncertainties of property values derived from a charge-density model is not straightforward. A methodology, based on calculation of sample standard deviations (SSD) of properties using randomly deviating charge-density models, is proposed with theMoProsoftware. The parameter shifts applied in the deviating models are generated in order to respect the variance–covariance matrix issued from the least-squares refinement. This `SSD methodology' procedure can be applied to estimate uncertainties ofanyproperty related to a charge-density model obtained by least-squares fitting. This includes topological properties such as critical point coordinates, electron density, Laplacian and ellipticity at critical points and charges integrated over atomic basins. Errors on electrostatic potentials and interaction energies are also available now through this procedure. The method is exemplified with the charge density of compound (E)-5-phenylpent-1-enylboronic acid, refined at 0.45 Å resolution. The procedure is implemented in the freely availableMoProprogram dedicated to charge-density refinement and modelling.


2009 ◽  
Vol 65 (6) ◽  
pp. 757-769 ◽  
Author(s):  
Louis J. Farrugia ◽  
Pavel Kočovský ◽  
Hans Martin Senn ◽  
Štěpán Vyskočil

The charge density in (±)-8′-benzhydrylideneamino-1,1′-binaphthyl-2-ol (1) has been studied experimentally using Mo Kα X-ray diffraction at 100 K, and by theory using density-functional thoery (DFT) calculations at the B3LYP/6-311++G** level. The nature of the weak intramolecular peri-C...N, CH...π, H...H and C(π)...C(π) interactions has been examined by topological analysis using the Quantum Theory of Atoms in Molecules (QTAIM) approach. An analysis of the density ρ(r), the Laplacian of the density ∇2ρ(r b) and other topological properties at the bond-critical points were used to classify these interactions. The study confirms the presence of the intramolecular CH...π interaction in (1), which was previously suspected on geometrical grounds. An analysis of the ellipticity profiles along the bond paths unambiguously shows the π-delocalization between the imine unit and one N-phenyl group. The weak intermolecular interactions in the crystal of (1) were examined experimentally and theoretically through the pairwise interactions of the seven independent dimeric pairs of (1) responsible for the set of unique intermolecular interactions, and also through examination of the Hirshfeld surface d norm property. The theoretical dimeric-pair calculations used the BLYP-D functional which supplements the exchange-correlational functional with an empirical dispersion term to provide a more accurate determination of the energies for the weak intermolecular interactions.


1981 ◽  
Vol 37 (5) ◽  
pp. 711-722 ◽  
Author(s):  
J. R. Schneider ◽  
N. K. Hansen ◽  
H. Kretschmer

2002 ◽  
Vol 730 ◽  
Author(s):  
Gianguido Baldinozzi ◽  
Michaël Dutheil ◽  
David Simeone ◽  
Andreas Leithe-Jasper

AbstractA charge density study of boron carbide B12C3 single crystals at different temperatures allows a quantitative description of the electron density responsible for chemical bonding. These results, based on direct observations, are compared to previous models of bonding. This description points out that structural features are more complex than suggested by simple qualitative models. The effects of chemical substitution, the characteristics of the interatomic bonding, the charge transfer and the bond strength are discussed and compared to the information obtained from previous conventional refinements and ab-initio calculations in disordered B12C3.


Sign in / Sign up

Export Citation Format

Share Document